[boost] Re: Conversion from auto_ptr to scoped_ptr?

From: Markus Schöpflin (markus.schoepflin_at_[hidden])
Date: 2002-06-17 03:59:54

Peter Dimov wrote:
> 
> From: "Markus Schöpflin" <markus.schoepflin_at_[hidden]>
> > Hello there,
> >
> > pardon me in advance if this is a FAQ but why is there no
> > costructor for scoped_ptr that takes a smart_ptr as an
-------------------------------------------^^^^^^^^^
Just spotted this, it should of course read auto_ptr!

> > argument?
> 
> I don't know. :-)
> 
> > Assuming, you have a funktion
> >
> > std::auto_ptr<Obj> create_obj();
> >
> > this would allow you to write
> >
> > std::scoped_ptr<Obj> p(create_obj());
> 
> No, unfortunately it will not. The constructor will take a non-const
> reference to auto_ptr, and those cannot be bound to rvalues. std::auto_ptr
> uses an interesting (and obscure) technique to allow
> 
> std::auto_ptr<Obj> p(create_obj());
> 
> and I'm not sure that we need to enable this functionality for scoped_ptr.
> 

Hmm, I did some further thinking on this and I simply can't see the
difference between the current shared_ptr, which offers a conversion from
auto_ptr and my suggestion for scoped_ptr.

Could you enlighten me, Peter? Or anybody else?

TIA, Markus